In Aikido, as in virtually all Japanese martial arts, there are both physical and mental aspects of training. The physical training in aikido is diverse, covering general physical fitness and conditioning, as well as specific techniques. Because a substantial portion of any aikido curriculum consists of throws, the first thing most students learn is how to safely fall or roll. It is not a static art, but places great emphasis on motion and the dynamics of movement. The specific techniques for attack include both strikes and grabs; the techniques for defense consist of throws and pins. Physical training goals pursued in conjunction with aikido include controlled relaxation, flexibility, and endurance.